Pipeline maintenance and management in inter-tidal region - a case study

摘要

The pipeline system is regarded as the safest and the most economical system for transportation of hydrocarbons across the country. Pipelines of various sizes and lengths crisscross the continents supplying both processed as well as unprocessed crude oil and gas from the producing region to the consumer. Though the advent of pipeline and its development occurred concurrently with the development of the hydrocarbon industry, but like the oil industry, the pipelines also keep on throwing new challenges requiring human ingenuity. The present paper presents the approach taken by the National Oil Company of India in maintaining and operating a 36" pipeline transporting unprocessed sour gas (150-160 ppm of H2S and nearly 7% CO2) from offshore field to the onshore gas processing plant. The paper explores the various options evaluated to maintain the health of the pipeline which travels through various profiles with special attention to the landfall point, where the pipeline faces alternating exposure of a dynamic meandering river which has changed its course many a times resulting in generation of free spans.